While the physical destruction wrought by hurricane Katrina may have been widespread, it may be anticipated that the long term impact on behavioral health may not be equally distributed in the community. Individuals at risk for drug abuse may have been especially affected and may remain especially vulnerable. In collaboration with both the major academic institutions in the area (Tulane University and Louisiana State University), we propose an R21 formative study with the overall goal of understanding the impact of this kind of natural disaster on situational adaptation among drug users. The design and methods of the proposed study are informed by theory and methods from Anthropological Ethnography---"Ethno-Epidemiology", an approach we have successfully applied in a number of prior public health studies in out-of-treatment populations and settings. Situated in New Orleans, the study will begin with a Community Assessment Process (CAP) which will be used to describe the geographic, temporal, and social distribution of street drug use in post-Katrina New Orleans, particularly in relation to use of heroin, cocaine, and crack-cocaine. Following this initial formative assessment, we will recruit a modest size sample of active street drug users and follow them for one year, conducting monthly interviews with the general goal of assessing post Katrina adaptations related to drug abuse and HIV risk. Assessment tools will include ongoing ethnographic observation as well as detailed ethnographic interviews which will include a series of event-oriented modules that are aimed at illuminating situational-decision making. Findings will be disseminated directly to local treatment and service professionals, and the technical capacity developed through the collaboration with local universities will enhance the local research capacity to apply these research methods to out-of-treatment populations and settings. [unreadable]